Cambridge IGCSE Science - Combined 0653 — 2013 Oct/Nov Paper 2 · Variant 1

This document consists of 23 printed pages and 1 blank page. IB13 11_0653_21/5RP © UCLES 2013 [Turn over *9413954228* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/21 Paper 2 (Core) October/November 2013 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 24. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 1 Sodium chloride is obtained from underground deposits in the Earth’s crust or from solutions such as sea water. (a) (i) Explain why the Earth’s crust contains the compound sodium chloride and not the uncombined elements, sodium and chlorine. [1] (ii) State one difference between a compound and an element. [1] (iii) Describe how crystals of sodium chloride could be obtained from a salt solution. [2] (b) The chemical formula of the compound calcium fluoride is CaF2. Explain the meaning of the numbers in this formula. [1]

3 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (c) Fig. 1.1 shows apparatus used to separate the element lead from the compound lead bromide. low voltage d.c. supply + – molten lead bromide Fig. 1.1 (i) Name the process shown in Fig. 1.1. [1] (ii) Explain why an orange-coloured gas is observed rising from the molten lead bromide during the process. [2]

4 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 2 Fig. 2.1 shows the inside of a refrigerator. The temperature inside the freezing compartment is -20 °C and the temperature in the rest of the refrigerator is +5 °C. freezing compartment Fig. 2.1 (a) The air in the refrigerator is cooled by convection. Draw one arrow on Fig. 2.1 to show the movement of the air cooled by the freezing compartment. [1] (b) The volume of air in the refrigerator is 0.15 m3. The density of air is 1.26 kg / m3. Calculate the mass of air in the refrigerator. State the formula that you use and show your working. formula working kg [2]

5 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (c) (i) Complete the diagrams to show the arrangement of water molecules in solid ice and in liquid water. One molecule has been drawn for you in each box. Each diagram should contain at least twelve water molecules. solid ice liquid water [2] (ii) Each sentence describes either a solid, a liquid or a gas. In the right hand column write the letter S for solid, L for liquid or G for gas to match the description. description S, L or G It cannot flow. It cannot transfer heat by convection. It contains particles which are widely separated. It expands the most when heated. It fills a closed container. It has a fixed volume but not a fixed shape. [2]

6 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 3 The concentration of glucose in the blood does not normally vary much. The hormone adrenaline causes blood glucose concentration to increase. (a) (i) Define the term hormone. [2] (ii) State one effect of adrenaline on the body, other than increasing the concentration of glucose in the blood. [1] (b) Researchers investigated how adding fibre to foods affected the concentration of glucose in the blood after eating. Fig. 3.1 shows the results that they obtained for two different types of cornflakes. Cornflakes contain a lot of starch. 8 6 4 2 0 0 20 40 60 time / minutes 80 100 120 blood glucose concentration / arbitrary units cornflakes with cornflakes with no added fibre no added fibre cornflakes with cornflakes with added fibre added fibre cornflakes with no added fibre cornflakes with added fibre cornflakes eaten Fig. 3.1

7 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use Use the information in Fig. 3.1 to help you to answer the following questions. (i) Describe how the blood glucose concentration changed after eating cornflakes with no added fibre. [3] (ii) Describe how adding fibre to the cornflakes affected the changes in blood glucose concentration after eating. [3] (c) Outline one other way in which fibre in the diet affects health. [1]

8 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 4 Fig. 4.1 shows a period in the Periodic Table. Four elements are represented by letters which are not their usual chemical symbols. W 1 group number X 2 3 4 5 6 Y 7 Z 0 Fig. 4.1 (a) (i) State and explain which of the elements, chosen from W, X, Y and Z, are poor conductors of electricity. element(s) explanation [2] (ii) One of the elements shown in Fig. 4.1 is not expected to form a compound with any of the others. State and explain which one of the elements this is. element explanation [2]

9 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (b) Fig. 4.2 shows the melting points of four metallic elements from the same group of the Periodic Table. 200 100 0 0 10 20 30 40 50 60 70 proton number melting point / °C Fig. 4.2 (i) State the number of the group that contains the elements whose melting points are shown in Fig. 4.2. Explain your answer briefly. group number explanation [2] (ii) Use the Periodic Table on page 24 to name the element in Fig. 4.2 that has the lowest melting point. [1]

10 © UCLES 2013 0653/21/O/N/13 For Examiner's Use (c) (i) Copper oxide is a black solid which is insoluble in water. A student added excess dilute sulfuric acid to some copper oxide and warmed the mixture. The copper oxide disappeared and a clear blue solution remained. State one observation which shows that a chemical change has occurred. [1] (ii) Complete the word chemical equation for the reaction between copper oxide and dilute sulfuric acid. copper oxide + sulfuric acid + [2]

11 © UCLES 2013 0653/21/O/N/13 [Turn over Please turn over for Question 5.

12 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 5 Fig. 5.1 shows a solar-powered vehicle which travelled 3000 km in 30 hours. Fig. 5.1 (a) Calculate the average speed of the vehicle in km / hr. State any formula that you use and show your working. formula working km / hr [2] (b) Fig. 5.2 shows a speed / time graph for part of the journey. 0 0.5 1.0 time / hours 1.5 2.0 160 140 120 100 80 60 40 20 0 speed / km per hour A B A C Fig. 5.2

13 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (i) What was the maximum speed of the vehicle? km / hr [1] (ii) Describe the movement of the vehicle between A and B. [1] (c) Fig. 5.3 shows the energy flow diagram for the solar-powered vehicle. solar energy solar cell 90% reflected off solar cell 30% lost to environment electric motor 10% transferred to motor 70% transferred to kinetic energy of vehicle Fig. 5.3 During part of the journey, the solar cell receives 1 000 000 joules of solar energy. Calculate the number of joules transferred as kinetic energy to the vehicle. Show your working. J [2] (d) Solar energy is a renewable energy source. (i) Name one other renewable energy source. [1] (ii) Describe one advantage to the environment of using solar energy as a renewable energy source. [1]

14 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 6 Fig. 6.1 shows a section through the heart. pulmonary artery pulmonary vein A B Fig. 6.1 (a) Name the parts labelled A and B. A B [2] (b) The walls of the heart are made of muscle. Explain how this muscle pushes blood out of the heart. [2] (c) Suggest why the muscle of the upper chambers of the heart is thinner than the muscle of the lower chambers of the heart. [2]

15 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (d) When the heart is beating more quickly than usual, it uses a lot of oxygen. Suggest why the heart uses more oxygen when it is beating quickly. [2]

16 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 7 (a) (i) Name a raw material that provides us with hydrocarbons. [1] (ii) Explain the meaning of the term hydrocarbon. [1] (iii) Fig. 7.1 shows the chemical equation for the reaction between ethene and bromine, set out as molecular structures. C C H H H H Br Br Br Br C C H H H H + Fig. 7.1 Rewrite the information in Fig. 7.1 using chemical formulae. One chemical formula has been given. C2H4 + [2]

17 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (b) Propane is a gaseous hydrocarbon used as a fuel. Fig. 7.2 shows a cross-section through a small furnace (kiln) in which items of pottery are being heated by a propane burner. The temperature inside the kiln is 950 °C. waste gas mixture 950 °C propane kiln walls made from insulating material air Fig. 7.2 (i) State which information from Fig. 7.2 shows that the combustion of propane is exothermic. Explain your answer. [2] (ii) Suggest two compounds that have a higher concentration in the waste gas mixture than in the air drawn in at the bottom of the kiln. Explain your answer briefly. 1 2 explanation [3]

18 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 8 (a) Complete Table 8.1 below by drawing the circuit symbol for each electrical component. Table 8.1 name of component circuit symbol open switch resistor voltmeter fuse [2] (b) Fig. 8.1 shows an electrical hazard. outer insulation inner insulation copper wire Fig. 8.1 State the hazard. Explain why this situation is dangerous. [2]

19 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (c) In the circuit shown in Fig. 8.2 the reading on ammeter A3 is 0.5 A. (i) State the current readings on ammeters A1 and A2. A3 A A A A1 A2 Fig. 8.2 A1 A A2 A [1] (ii) Each lamp in the circuit has a resistance of 5 Ω. Calculate the combined resistance of the two lamps in the circuit. State the formula that you use and show your working. formula working Ω [2]

20 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 9 (a) Fig. 9.1 shows a plant cell. chloroplast vacuole membrane cellulose cell wall large permanent vacuole nucleus cell membrane cytoplasm Fig. 9.1 (i) Describe the function of the cell membrane. [1] (ii) Name two structures labelled on Fig. 9.1 that are not found in animal cells. 1 2 [2] (iii) Describe how photosynthesis is carried out in the cell shown in Fig. 9.1. [3]

21 © UCLES 2013 0653/21/O/N/13 [Turn over For Examiner's Use (b) About one tenth of the Earth's surface is covered by forests in which much photosynthesis takes place. List three ways in which extensive deforestation could harm the environment. 1 2 3 [3]

22 © UCLES 2013 0653/21/O/N/13 For Examiner's Use 10 (a) Fig. 10.1 represents the electromagnetic spectrum. gamma rays X-rays ultraviolet visible light infra red microwaves radio waves Fig. 10.1 Name the type of electromagnetic wave that is used (i) to send a signal to a TV from a remote control, [1] (ii) to send satellite TV information. [1] (b) Fig. 10.2 represents a wave. 300 metres 3 metres 3 metres 3 metres Fig. 10.2 Use Fig. 10.2 to find the wavelength of the wave, m amplitude of the wave. m [2]

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24 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2013 0653/21/O/N/13 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2013 series 0653 COMBINED SCIENCE 0653/21 Paper 2 (Core Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2013 series for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level components. www.XtremePapers.com

Page 2 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 21 © Cambridge International Examinations 2013 1 (a) (i) reference to reactivity of elements / compound is more stable ; [1] (ii) element cannot be simplified / decomposed chemically ; element contains just one type of atom ; element is found in Periodic Table ; [max 1] (or corresponding answers for compound) (iii) heat / boil solution ; water evaporates leaving sodium chloride ; leave to evaporate ; [max 2] (b) idea that formula shows the ratio Ca:F particles is 1:2 ; [1] (c) (i) electrolysis ; [1] (ii) bromine is formed ; bromine (vapour) is orange ; bromine evaporates / boils off ; [max 2] [Total: 8] 2 (a) arrow going downwards ; [1] (b) mass = density × volume ; = 1.26 × 0.15 = 0.19 kg ; [2] (c) solid – all particles touching, regular arrangement particles of similar size ; liquid – most particles touching, irregular arrangement particles of similar size ; [2] (d) description S, L or G It cannot flow S It cannot transfer heat by convection S It contains particles which are widely separated G It expands the most when heated G It fills a closed container G It has a fixed volume but not a fixed shape L [2] [Total: 7]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 21 © Cambridge International Examinations 2013 3 (a) (i) substance produced by a gland carried in blood affects activity of target organs destroyed by liver ;; [max 2] (ii) increases heart rate / increases breathing rate / sweating / pupil dilation / increases pulse rate / faster reactions / increases rate of respiration / increase in oxygen to muscles/brain ; accept any correct answer [1] (b) (i) increased then decreased increased more rapidly than it decreased maximum 6.6 units /at 40 minutes quote figures, e.g. returned to normal by 100 minutes ;;; [max 3] (ii) (blood glucose concentration) did not rise as high maximum 4 units rather than 6.6 units rose more slowly fell more slowly took longer to return to normal ;;; [max 3] (c) reduces, constipation / bowel cancer / risk of diabetes ; [1] [Total: 10] 4 (a) (i) Y and Z ; non-metals ; [2] (ii) Z ; it is a noble / inert gas / ref to filled shells in atoms ; [2] (b) (i) Group 1 ; reference to at least one of the proton numbers plotted on graph ; [2] (ii) rubidium ; [1] (c) (i) insoluble substance dissolved / disappeared colour change / coloured substance produced ; [max 1] (ii) (reactants→) copper sulfate ; + water ; [2] [Total: 10]

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 21 © Cambridge International Examinations 2013 5 (a) speed = distance/time ; = 3000/30 = 100 km/hr ; [2] (b) (i) 120 km/hr ; [1] (ii) changing speed / going faster / accelerating ; [1] (c) 1,000,000 × 0.10 × 0.70 ; = 70,000 J ; [2] (d) (i) geothermal/tides/hydroelectric/waves/wind/biomass ; [1] (ii) fossil fuels not wasted no CO2 produced ; [max 1] [Total: 8] 6 (a) A (right) atrium ; B (right) ventricle ; [2] (b) contracts ; reduces volume of ventricle ; increases pressure ; [max 2] (c) needs to produce less force ; to push blood into ventricle ; not out of the heart ; [max 2] (d) uses more energy ; energy obtained by respiration ; respiration uses oxygen ; [max 2] [Total: 8]

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 21 © Cambridge International Examinations 2013 7 (a) (i) petroleum / crude oil / natural gas ; [1] (ii) compound of hydrogen and carbon only ; [1] (iii) C2H4 + Br2 ; → C2H4Br2 ; [2] (allow Br2 anywhere in product formula) (b) (i) the temperature (inside kiln) is high / is 950 °C ; exothermic means the reaction releases heat (energy) ; [2] (ii) carbon dioxide carbon monoxide water (vapour) two of the above with produced by combustion of propane / hydrocarbons ;;; [max 3] (ignore refs to complete combustion) [Total: 9] 8 (a) Correct symbol for [2] (b) damaged insulation/bare wires ; danger of electrocution ; [2] (c) (i) 0.5 A 0.5 A ; (need both) [1] (ii) R = R1 + R2 ; = 10 Ω ; [2] [Total : 7] V open switch resistor voltmeter fuse

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0653 21 © Cambridge International Examinations 2013 9 (a) (i) controls what enters / leaves the cell ; [1] (ii) cell wall ; chloroplast ; large permanent vacuole ; vacuole membrane ; [max 2] (iii) takes place in chloroplasts ; chlorophyll absorbs / traps, sunlight / energy from sunlight ; water combines with carbon dioxide ; produces oxygen and glucose / sugar / carbohydrate ; [max3] (b) extinction ; soil erosion ; flooding ; build up of carbon dioxide ; drought ; increase in global warming ; [max 3] [Total: 9] 10 (a) (i) infrared ; [1] (ii) microwaves ; [1] (b) 100 m ; 1.5 m ; [2] [Total: 4]